seawater pump failure on merc I/O 7.4 - more damage?

[oldbuck]

Re: seawater pump failure on merc I/O 7.4 - more damage?

searched around and didn't see anything in the adult pages on pressure testing the block (there is an outdrive pressure test topic). Am I looking in the wrong place?

thx,
-d

 

[OldNBold51]

Re: seawater pump failure on merc I/O 7.4 - more damage?

Water in oil is not a good sign but......... the water could have gotten past the rings during the near meltdown. The 454 is a tough SOB so if you shut down soon enough you may be OK.

I'd change the oil using Rotella diesel oil, or another diesel oil brand so as it's cheap. Take it to the water (not with muffs) and run it(not idling, but under load...hole shots and rpm dashes) while constantly checking the dipstick for froth/water. Don't get far from the ramp. 5-10 minutes of a load will tell if you've got a crack. If it's frothy, idle back to the ramp and load up. This motor is built for tough duty, so idling with frothy oil won't kill your bearings/journals ( I know 1st hand).

This will be a definitive test and if it passes, the diesel oil works real well ( I know 1st hand) for every day use.

 

[oldbuck]

Re: seawater pump failure on merc I/O 7.4 - more damage?

thx oldnbold! - I'll give that a shot tomorrow. Should I change the filter too or is that just wasting money at this point?